This invention relates generally to a method of harvesting sugarcane and a combine that is useful for harvesting sugarcane. Although the invention is especially useful for harvesting sugarcane, it may be used to harvest other food-producing plants, such as corn, or as a bush hog to clear fields of stalk-like growth.
Sugarcane has been harvested manually until recently. As available labor decreases in supply, mechanical combines, or harvesters, have been introduced to automate the harvesting process. The known mechanical combines utilize knives supported by a vehicle which is propelled by caterpillars or treads. The mechanical combine cuts the entire stalk close to the ground and cuts the stalk into lengths of approximately 18 inches or more and ships the stalks to a processing plant. The processing plant removes the foliage which is shipped back to the field for reintroduction to the soil as fertilizer.
Such known mechanical combines have numerous disadvantages. Because the stalk tends to weep at the cut, it is necessary to maintain the length of the stalk as long as possible in order to avoid excessive loss of glucose. Also, bacteria in soil tend to enter the stalk at the cut and cause a process within the stalk that tends to reduce sugar production. This necessitates rapid processing of the cane before the bacteria-based process further reduces yield.
Another difficulty with existing harvesting techniques is the burning of the foliage. This is done to expose the base of the stalk to allow the combine operator to view the stalk/soil interface, as well as to dispose of the foliage. The burning of foliage has become a health hazard not only to the farm workers and local residents, but also to vehicles traveling local highways that may have difficulty seeing because of the smoke density. This has led to an outlawing of burning in some areas where sugarcane is grown.
Additionally, handling of the foliage waste is a significant cost of the process. The foliage waste must be physically removed from the stalk at the processing plant and shipped back to the field for reintroduction to the soil. All of this adds cost to the process. Indeed, it is estimated that up to 75 percent of the hauling cost associated with harvesting sugarcane with a mechanical combine is in handling the foliage.
The present invention provides a method of harvesting sugarcane in a manner that reduces difficulties created by traditional mechanical harvesting of sugarcane stalks. In particular, the present invention significantly reduces the loss of glucose from the weeping at the harvesting cut. It also significantly reduces the entrance of bacteria at the cut, thereby increasing sugar yield. Moreover, because the present invention reduces weeping and bacteria contamination, it allows the stalk to be cut into smaller sections. This allows the bulk of the foliage to be removed as part of the harvesting process because the foliage naturally is removed from a stalk cut into small sections.
A method of harvesting sugarcane having a stalk, according to an aspect of the invention, includes generating at least one laser beam and causing at least one laser beam to at least momentarily come into contact with the sugarcane thereby severing the stalk and substantially cauterizing the stalk where severed. Among the many advantages that are provided, this substantially reduces loss of glucose and contamination of the glucose with bacteria from the soil.
The laser beam may be scanned across the sugarcane stalk, such as approximately a diameter of a sugarcane""s stalk. The sugarcane may be cut into a plurality of sections. A fluid may be flowed past the sections to remove foliage waste. The sections may be tumbled to assist in removing the foliage waste. The sugarcane stalk may be cut into a plurality of sections that are less than one foot in length and may be less than one-half of a foot in length.
The at least one laser beam may be focused at a distance of less than one foot and may be focused at a distance of four inches or less. The distance of the at least one laser beam from the ground may be controlled, such as by sensing the ground with a non-contact sensor. A non-contact sensor may be a laser sensor, an ultrasonic sensor, and/or a radar sensor.
The at least one laser beam may be generated by a laser beam source. The laser beam source may be supported with a vehicle having pneumatic tires. The laser beam source may be supported with a vehicle having an electrical generator for powering the at least one laser source.
An agricultural combine apparatus, or harvester, according to another aspect of the invention, may include at least one laser projecting a laser beam and a support. The support supports the at least one laser to position the beam to intersect a stalk of a plant.
These and other objects, advantages and features of this invention will become apparent upon review of the following specification in conjunction with the drawings.